Electrical connector with flexible contacts



1959 M. J. AINSWORTH 2,

' ELECTRICAL CONNECTOR WITH FLEXIBLE CONTACTS Filed Sept. 15. 1953 Fig. 1

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RESIL/EAIT m RES/LIENT INVENTOR MQM ELECTRICAL CONNECTOR WITH FLEXIBLE CONTACTS Merrill J. Ainsworth, Northridge, Calif.

Application September 15, 1953, Serial No. 380,259

5 Claims. (Cl. 33917) This invention relates to an improved construction of electrical connecting devices and to electrical connecting devices based upon this construction.-

One of the problems in assembly of electrical and electronic equipment is appropriate and satisfactory con- :nection between the various sub-assemblies and assemblies which comprise an operating system. This problem has been accentuated in recent years by the advent of the printed or process formed circuit to which prior con- :nection schemes are poorly adapted.

The typical connecting device in common present usage :generally comprises an insulating molding or fabrication into which machined or formed contacts are individually inserted and locked in place during manufacture. Each contact is so fabricated as to provide spring or contact pressure on its mating contact within the limits of the spring retention qualities available in the limited amount of material in the typical contact. Physical abuse or strain of the contact beyond the yield point of the material renders the contact useless until repaired or replaced.

One object of this invention is to provide a basic electrical connector design in which each individual electrical contact is dependent not only upon its inherent spring tendencies for contact pressure but is intimately backed with a resilient confined electrical insulator which is loaded under compression to provide contact pressure. Such compression loaded backing may provide the total contact pressure required in the connector or may provide supplemental pressure to that inherent in the contact.

Another object of this invention is to provide electrical connectors which are completely compatible with electrical and electronic circuit constructions of the printed circuit type.

Another object of this invention is to provide a method whereby electrical connectors can be manufactured with simultaneous assembly of all contacts instead of the laborious and costly individual contact installation now employed.

Another object of this invention is to provide an electrical connector with terminals for external connection which are sufliciently flexible to permit orientation and adjustment to mating wire cable assemblies or printed connector patterns.

Another object of this invention is to provide a basic electrical connector construction which can be smaller in size than prior and conventional connector constructions in keeping with requirements for miniaturization of electrical and electronic equipments.

United States Patent Another object of this invention is to provide a basic electrical connector construction in which the individual pins and contacts are not susceptible to mechanical damage as in present and prior constructions.

Another object of this invention is to provide a basic electrical connector construction in which alignment of all pins and contacts is positive and assured eliminating the need for floating contact construction predominant in present and'prior constructions.

Another object of this invention is to provide the basic design for an electrical connector which could be conven- 2,874,363 Patented Feb. 17,- 9

iently mounted upon or attached to related structures or assemblies by the same fasteners employed in assembly of the connector.

Another object of this invention is to provide a connector construction which will accomplish polarization of the mating parts of the connector inherent in the mechanical design without reliance on external or internal accessory devices to insure correct insertion.

The objects of my invention are accomplished by the design, materials, construction and assembly of parts to be hereinafter more specifically pointed out and claimed, and said construction is produced by the methods hereinafter also set forth-and particularly claimed. A complete understanding of the invention and of the various features thereof may be gained from a consideration of the following detailed description in connection with the annexed drawings in which:

Figure 1 is a front view of a punched and/or formed part comprising all contacts of the female portion of an electrical connector together with supporting and locating material for those contacts.

Figure 2 is an end view of the parts comprising one half of the female portion of an electrical connector showing their arrangement and orientation prior to laminating.

Figure 3 is an end view of one half of the female portion of an electrical connector after lamination of the parts, severance of the supporting and locating material, and simultaneous forming of the contacts.

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Figure 4 is an end view of the completely assembled connector.

Figure 5 is a front view of the completely assembled make contact with the female contacts of the connector.

Figure 7 is a front view of the male portion of the connector as fabricated from a commercial copper-clad laminate for use in cable to cable connection employing this connector.

Fig. 8 is a plan view of the female connector; and

Fig. 9 is a transverse sectional view of the same, taken on the line 9-9 of Fig. 5.

Referring now to the drawings there is shown in Figure 1, a part 1 as punched from an appropriate metal, for example copper, which comprises multiple electrical contact strips together with end bars serving to locate the contact strips with respect to each other and to permit their multiple handling in subsequent operations. Holes 2 drop over pins to simultaneously and accurately locate all contacts during the lamination step to be described.

Suitable metals for part 1, in addition to copper, include, but are not limited to aluminum, silver, gold, nickel, platinum, and rhodium.

Figure 2 shows the pile up ready for lamination. Cover 3 is an insulating layer which insulates and protects embedded ends of contacts in the complete assembly. Rigid backing member 4 is an insulating layer which provides stiffness to the structure and a non-yielding backing for the resilient compressible pad 5 when it is compressively loaded in use. The layer 5 may be constituted of natural rubber, or a material of synthetic origin including but not limited to silicone rubber,'neoprene, Buna N, Buna S, Butyl, reclaim and other rubber-like materials. The insulating layers 3 and 4 may be fabricated from laminate sheet material of glass cloth and a resin selected from the group including but not limited to melamine, urea, nylon, vinyl, polyethylene, epoxy, polyesters, polytetrafluoroethylene, and monochlorotrifluoroethylene; or from a laminate of a phenolic resin with paper or cloth; or

the final position and one retaining bar has been severed and discarded. Theother'retaining bar is also severed' and discarded in producing the completed connector.

In Figure 4 is illustrated an end view of the completed female connector in which two of the laminatedetructures of Figure 3 have been assembled toan insulating barrier core 6 and fastened by means of rolled head eyelets '7. The remaining retaining bars have been's'evered from the ends of the contact strips and discarded leaving each contact electrically isolated. Thickness of the insulating barriercore 6 is slightly less than' that of the male'portion'of the connector or the mating printed circuit and this difference in thickness represents the amount of compression conveyed to the'res'ilient member 5 upon insertion of the male portion of the connector. "This compression and the hydraulic action of -the resilient material provides uniform and reliable contact pressure to the entire contact area rather than to the small area represented in spring metal contacts of prior construction.

Referring now to Figure 5, a front view of the complete female connector is shown. pins 8, one or more of which may be employedto polarize insertion of the male portion of the connector to insure its insertion in correct relationship to the female.

The male portion of the connector may'take many forms of outstanding simplicity due to the fact that total accommodation for manufacturing irregularities is inherent in the resilent structure of the female portion of the connector.

Referring now to Figures 6 and 7, shown are two configurations of the male portion of the connector. Figure 6 illustrates a typical printed circuit produced by any of the techniques known to the art. The body material 9 carries the circuitry, printed conductors of which terminate in lines at the edge of the circuit 10 spaced to correspond to spacing of contacts in the female connector. Figure 7 shows a male connector for cabling connection produced by printed circuit methods but accommodating attachment of individual wires of a cable 11 to the male portion of the connector. polarizing key-way by engaging with eyelet 8 of Figure 5 to insure correct positioning of the male connector in the female upon insertion.

While certain embodiments of the invention have been selected fordetailed description, the invention is not, 'of course, limited in its application to the embodiments described. These embodiments should be taken as iillustrative'of the invention rather than restrictive thereof. I am awarethatprior"to my invention, electrical connectors have been made having spring metallic ribbon contacts. Itherefore do not claim such a construction broadly; butIclaim':

1. A female electrical connector in the form of a sandwich comprising: a rigid core; a pair of opposed, re-

silient, compressible pads embracing said core; a pair of rigid backing membersembracing said pads; opposed contactor bars interposed between respective sides of said core and respective pads; and securing elements exte'nding through said core, pads and backing members andbinding them together tightly in said sandwich; said contactor bars, pads andbacking members projecting beyond one side of said core'to define a socket wherein said contac'tor'bars are exposed for reception of a male connector between them; said pads functioning as cushions for yieldingly accommodating spreading of said contactor bars to receive the male element and for yieldingly pressing said contactor bars against the male element;

'2. "A connectoras definedinclaim 1, includingconnector tabs formed as'integral extensions of saidcontactor bars, projecting from thesidepf said sandwich opposite Said Sock tf i 3'. A female electrical connector in the form of a sand- Also shown here are small The slot shown 12 serves asa wich comprising: a rigid core; a pair of opposed, resilient, compressible pads embracing said core; a pair of rigid backing members embracing;said pads; a pair of cover members embracing said backing members; opposed conductor parts of generally U-shape, each including a contactor leg interposed between a respective pad and a respective side of said core, a, back leg engaged between the respective backing member and the respective cover member, and a return hend portion integrally joining the two legs; and securing elements extending through said core, pads, backing members and cover members and clamping them together in said sandwich; said contactor bars,pads and backing members projecting beyond one side of said core todefine a socket wherein said contactor bars are exposed for"reception of a male connector between them; said pads functioning as cushions for yieldingly accommodating spreading of the respective halves ofthe connector to receive the male element, and

for yieldingly'exerting pressure biasing the halves toward their normal position, thereby pressing the contactor legs against the male connector.

4. An electrical connector apparatus consisting in female and male connector'members, said female connector, being, a sandwich comprising a rigid core; a pair of opposed, resilient, compressible pads embracing said core; a. pair of/rigid backingmembers. embracing said pads; a pair of cover members embracing saidbacking members; opposed conductor parts of generally U-shape, each including a contactor leg interposed between a respective'pad'and a respective side of said core, a back leg engaged between the respective backing member and the respectivecover member, and a, return-bend portion integrally joining the two legs; and securing elements extending throughsaid core, pads, backing members and cover members andclamping them together in said sandwich;.said contactor bar's, padsand backing members and cover members'projecting beyond one side of said core andbeing of elongated form to define an elongated socket wherein'said contactor bars are exposed for reception of a male connector between them, there being a plurality of. pairs' of the conductor parts arranged in spaced relation along the length of said socket; and a male connector comprising abody member in the form of a fiat bar'having a' thickness approximately corresponding to thewidth of said elongated socket, and a plurality of conductor strips printed onthe respective opposite side faces of said body member in positions to be engaged between the contactor legs of said female connector member; said pads functioning as'cushions for yieldingly accommodating spreading of the respective halves of' the female connector, with said backing plates tilting with respect to said core, to receive saidmale connector and said pads yieldingly exerting pressure biasing the respective halves toward their normal position and thereby pressing the contactor legs against the conductor strips ofthe male connector.

5. A connector apparatus as defined in claim 4, wherein said body of the maleconnectoris of relatively rigid material.

ReferencesCitedin the file of this patent N ED ATES PAT OTHER REFERENCES Tele-Tech, January. .1953, pages 64 --66. 

